Duplicating key machine and method of operating same

ABSTRACT

A key duplicating machine and the method of operating the machine wherein one or more key cutters move linearly along an axis perpendicular to the rotation of the key cutters. The linear movement enables the cutters to precisely cut a single sided or double sided key blank to a profile corresponding to the key to be duplicated. In addition, the key to be duplicated and the key blank are clamped together in a single operation in one clamping unit with one clamping force.

FIELD OF THE INVENTION

The present invention relates to a machine for duplicating keys and themethod of operating the machine. More particularly, the inventionrelates to a duplicating key machine and the method of operating themachine wherein one or more key cutters move linearly along an axisperpendicular to the rotation of the key cutters. The linear movementenables the cutters to penetrate and precisely cut a single sided ordouble sided key blank to a profile corresponding to the key to beduplicated. In addition the key to be duplicated and the key blank areclamped together in one clamping unit with one clamping force in asingle operation.

BACKGROUND OF THE INVENTION

Various types of duplicating key machines are known in the prior art.With the most common type of duplicating machines, both the key blankand the key to be duplicated are rigidly secured to the same shaft whichrotates about its longitudinal axis to move the blank key against thecutting wheel during the cutting operation. Moreover, in the prior artdesigns, the key blank and the key to be duplicated are clamped toseparate clamping units, each operated by a different clamp mechanismand tighten by separate handles so that each key is clamped by adifferent compressive force. The design of these prior art machinesresults in machines which are quite expensive to produce and maintain.Also, because of the inefficient and unreliable machine performance ofthe prior art designs, a high percentage of unusable keys are produced.

OBJECTS AND SUMMARY OF THE INVENTION

It is an object of the present invention to provide a duplicating keymachine and method of operating the machine which obviates the problemsand limitations of the prior art systems.

It is a further object of the present invention to provide an improvedduplicating key machine and method of operating the machine wherein thekey cutters move both in a linear, parallel direction and rotationallywith respect to a longitudinal axis through the key cutters.

Yet another object is to provide an improved duplicating key machine andmethod of operating the machine wherein the key guides which engage thegrooves in the key to be duplicated and move the cutters to cut anidentical groove in the key blank reciprocate in a linear, paralleldirection with respect to the longitudinal axis about which the cuttersrotate.

Still another object of the present invention is to provide aduplicating key machine and method of operating the machine which cutsboth double sided and/or single sided key blanks.

The present invention discloses an improved duplicating key machinewhich includes a number of innovative features. One or more cuttingwheels are mounted to both rotate about and move linearly with respectto a single axis through the cutting wheels.

According to a further preferred feature of the invention, the key to beduplicated and the key blank are clamped by the same clamping unit whichis connected to a support that moves perpendicular to the axis aboutwhich the cutters are rotating.

A further preferred feature to the invention is that the key to beduplicated and the key blank are clamped substantially perpendicular tothe axis about which the cutters rotate. Further, the key to beduplicated and the key blank are clamped with a single clamping unit ina joint tightening operation. The vector of the compressive force of theclamping unit is directed through both keys to be duplicated and the keyblank for effective use of the compressive force. Further, the key blankand the key to be duplicated are moved into and out of engagement withthe cutting unit by a single guiding mechanism in the clamping unit andsingle guiding operation. This feature is important for the accuracy ofsuch guidance. The clamping unit also includes a key alignment guidewhich ensures that the key blank and the key to be duplicated are inproper alignment during the clamping operation. This alignment guide isdisengaged when the clamping unit moves towards the cutting unit.

According to the invention, one embodiment of the key duplicatingmachine comprises a support to which a clamping unit for clamping onesided keys and a clamping unit for clamping two sided keys are mounted.This feature enables the same machine to be used for cutting both onesided and two sided keys by different clamping units.

BRIEF DESCRIPTION OF THE DRAWINGS

The structure, operation, and advantages of the presently preferredembodiment of the invention will become further apparent uponconsideration of the following description taken in conjunction with theaccompanying drawings, wherein:

FIG. 1 is a plan view of a key duplicating machine, partly incross-section, in accordance with the preferred embodiment of thepresent invention;

FIG. 2 is a side view taken through line 2--2 of FIG. 1, partly incross-section, illustrating the relationship of the key clamping unitwith respect to the cutting unit;

FIG. 3 is a side cross-sectional view taken through line 3--3 of FIG. 1,illustrating the cutting unit;

FIG. 4A is a cross-sectional view of the clamping unit through line4A--4A of FIG. 1 showing clamping units for a two sided key and a onesided key;

FIG. 4B is a cross-sectional view of an alternative embodiment of aclamping unit adapted for the two sided key clamping unit of FIG. 4A;

FIG. 4C is a plan view through line 4C--4C of FIG. 4A;

FIG. 4D is a perspective view of a compression component for theclamping unit of FIG. 4C;

FIG. 4E is side view, partly in cross-section, of an alternativeembodiment of a clamping unit adapted for the one sided key clampingunit of FIG. 4A;

FIG. 4F is a perspective view of a compression component for theclamping unit of FIG. 4E;

FIG. 5 is a side cross-sectional view of a key duplicating machine,similar to the key duplicating machine of FIG. 1 but with only twocutters;

FIG. 5A is a side view of a cutting guide;

FIG. 6 is a side view, in cross-section, of an alternative embodiment ofa key duplicating machine having a single key cutter with a singleguiding unit;

FIG. 7 is a cross-section of an alternative embodiment of the keyduplicating machine of FIG. 1 with an externally mounted biasing spring;

FIG. 7A is a view through line 7A--7A of FIG. 7;

FIG. 7B is a view through line 7B--7B of FIG. 7;

FIG. 7C shows the machine of FIG. 7 with the spring compressed forsingle cutter operation.

FIG. 8 is a side view, in cross-section, of an alternative embodiment ofa key duplicating machine; having a single cutter, a single guiding unitand a single rotational shaft;

FIG. 9 is a side view, in cross-section of an alternative embodiment ofa key duplicating machine having a single cutter mounted on a singlespring, longitudinally movable shaft; and

FIG. 10 is a side view, similar to FIG. 9 but with a plate-like cutter.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1, 2, and 3, a key duplicating machine 10 is shownincorporating the following novel features. A cutting unit 12incorporates one or more cup shaped milling cutters 12A, 12B, and 12C(also called cutting wheels), for cutting double and single sided keyblanks 14 and 16 to duplicate the profile of a double sided or singlesided keys 18 and 20, respectively. A unique feature of the invention isthat the milling cutters 12A--12C have both rotational movement aboutand linear reciprocal movement along the axis 22 extending throughcutting unit 12 during the key cutting operation. A key clamping supportstructure 24, on which is mounted one or more key clamping units 26 and28, reciprocally moves in a linear direction perpendicular to thelongitudinal axis 22. The clamping units 26 and 28 are each constructedto clamp the key to be duplicated and its associated key blank in asingle joint clamping operation using one compressive force. NOTE: Theduplicating key machine according to the present invention isconstructed to duplicate either one sided keys or two sided keys but bydifferent clamping units while the preferred embodiment of the keyduplicating machine 10 of the present invention is illustrated in FIG.1-3 and 4A, several alternative embodiments are shown in FIGS. 4B, 4C,5, 6, 7, 8, and 9. In order to better describe and explain the presentinvention, reference will be now made to the following FIGS. 1, 2, and3.

The duplicating key machine 10, in accordance with the presentinvention, includes a machine chassis 30 on which is mounted anelectrical motor 32 for driving the cutting unit 12, an eccentric diskor cam device 34 connected to a motor 36 for reciprocally movingclamping support structure 24 in a perpendicular direction to axis 22 bymeans of spring 224 illustrated in FIG. 2.

Reference is made now to the construction and parts of the cutting unit12 of the key duplicating machine 10. A partially hollowed cylindricalshaft 38 is rotatably supported at opposite ends with side bearings40,42 mounted within two upstanding chassis supports 44, 46,respectively, which in turn are coupled to machine chassis 30. Shaft 38has a fly wheel 48 mounted to one end, which is driven by a pulleytransmission strip 50 that is connected to fly wheel 52 attached tomotor 32. As shown in FIG. 3, milling cutter 12A is rigidly coupled to asliding cylindrical bearing 92 which in turn is disposed about the outerperipheral surface of shaft 38. As seen in FIG. 3, shaft 38 has twoelongated bored sections 54 and 56 which open at opposite ends 58 and 60of the shaft. Diametrically opposed elongated slots 62A, 62B and 64A,64B are located through the wall of shaft 38 adjacent the blind end ofbored sections 54 and 56, respectively. Note that the length of slots62A,62B are slightly longer than slots 64A,64B, for reasons which willbecome apparent in the discussion below. A spring 66 is disposed inbored section 54 and abuts against an end cap 68 at the outer end of thebore and against an elongated, cylindrical pin 70 which extends throughslots 62A,62B of shaft 38 for operational engagement with cutter 12A, asdiscussed below. The head of a pin 72 is biased by spring 66 intoengagement with pin 70. A spring 74 is disposed in bored section 56 andabuts against a hollow end cap 76 mounted within the outer end of thebore 56. End cap 76 has cylindrical end section 78 with diametricallyopposed slots 80,82 and an arcuate groove 84 formed in the end surfaceof end cap 76. The inner end of spring 74 engages against an elongated,cylindrical pin 86 which extends through slots 64A,64B of shaft 38 foroperational engagement with cutters 12B and 12C, as discussed below. Thehead of an elongated rod 88 which extends through bored section 56 andinto end section 78 of end cap 76 is biased by spring 74 into engagementwith pin 86. The outer end of rod 88 has a pin 90 secured therethroughand is slidably received in slots 80 and 82 in end section 78.

A first sliding cylindrical bearing 92 is slidably secured about theouter peripheral surface of shaft 38 by pin 70 and adapted for slidinglinear movement with respect to the shaft along the direction of axis22. Milling cutter 12A is mounted against inner shoulders of bearing 92so that the ends of pin 70 are received in slots 93 extending radiallyinward from central opening of cutter 12A to rotate cutter 12A with therotation of shaft 38. Abutted against cutter 12A is a circular bearingplate 94. A locking cap 96 is secured to the outer end of slidingcylindrical bearing 92. A cylindrical end section of cap 96 is providedto mount a cutting guide arm 100. The locking cap 96 secures the guidearm 100 against bearing plate 94 which in turn secures milling cutter12A to sliding bearing 92. As discussed in more detail below, millingcutter 12A both rotates about and reciprocates axially to axis 22 withcylindrical bearing 92 while cutting guide 100 is secured so that itonly reciprocates axially to axis 22.

A second sliding cylindrical bearing 102 is slidably secured about theouter peripheral surface of shaft 38 by pin 86 and adapted for sliding,reciprocal, linear movement with respect to the shaft along thedirection of axis 22. As shown in FIG. 3, second sliding cylindricalbearing 102 is normally abutted against first sliding cylindricalbearing 92. Milling cutter 12B is mounted against an inner shoulder ofbearing 102 so that the ends of pins 104 and 106 are received in a slots108 extending radially inward from central opening of cutter 12B torotate cutter 12B with the rotation of shaft 38. Abutted against cutter12B is a circular plate 109 having a cylindrical end section on which isseated a cutting guide arm 110. Abutted against plate 109 is a bearingplate 112. A milling cutter 12C is mounted against bearing plate 112 sothat the ends of pin 86 are received in slots 114 extending radiallyinward from the central opening of cutter 12C to rotate cutter 12C withthe rotation of shaft 38. Abutted against cutter 12C is a locking cap116 which is secured to the outer end of sliding cylindrical bearing102. The locking cap 116 secures the cutter against bearing plate 112which in turn secures cutting guide 110 against plate 109 so thatmilling cutter 12B is abutted against the shoulder of sliding bearing102. As discussed in more detail below, milling cutters 12B and 12C bothrotates about and reciprocates linearly to axis 22 with cylindricalsliding bearing 102 while cutting guide 110 is secured so that it onlyreciprocates axially to axis 22.

According to the invention cutting guide arm 100, as shown in FIGS. 1and 3, has a central section 116 with a hole 118 therethrough sized tobe seated on the cylindrical end section of cap 96. An upper guide armsection 122 with an elbow extends outward from central section 116 andhas a guiding blade 124 secured to the end thereof. A lower guide armsection 126 has a U-shaped end section 128 which is mounted to acomponent 130 which allows guide arm 100 to reciprocate in a lineardirection along axis 22 while preventing rotational movement thereabout.The component 130 is mounted within chassis support 44 and includes anelongated spring biased pin 132 which has an inner end that extendsbeneath U-shaped end 128 whereby the latter slidably engages pin 132between two spaced stops 134 and 136. The outer end of component 130extends through a hollow end cap 138 having a cylindrical end section140 with diametrically cut slots 142 and an arcuate groove 144 formed inthe end surface thereof. The inner end of a spring 146 is compressedbetween stop 136 and the inner bore of end cap 138 so that a pin 148 isseated against the arcuate groove 144 at the end of end cap 138. The pin148 can be turned into alignment with the slot 142 so that it is biasedinward to abut against the bottom surface of the slot whenever theduplicating machine is adjusted for single sided key duplication, asdiscussed below.

According to the invention, cutting guide arm 110, as shown in FIGS. 1and 3, has a central section 150 with a hole 152 therethrough sized tobe seated on the cylindrical end section of plate 109. An upper guidearm section 154 branches off into two arms elements 156 and 158, eachhaving a guiding blade 160, 162, respectively, secured to the endthereof. The guiding blade 160 is used in conjunction with guide blade124 for cutting two sided key blanks and the guide blade 162 is used forcutting single key blanks, as will become apparent from the discussionbelow. A lower guide arm section 164 has a U-shaped end section 168which is mounted to a component 170 which allows guide arm 110 to movein a linear direction along axis 22 while preventing rotational movementthereabout. The component 170 is mounted within chassis support 46 andincludes an elongated pin 172 with an inner end that is located beneathU-shaped end 168 whereby the latter slidably engages pin 172 between twospaced stops 174 and 176 which allows guide arm 110 to reciprocate in alinear direction along axis 22 while preventing rotational movementthereabout.

Referring to FIGS. 1 and 2, there is illustrated an upstanding keysupport 177 which is secured to chassis 30 and has a flat key supportingsurface 179 located just below key blank 14. As the key blank 14 ismoved into engagement with cutters 12A and 12B, the blade of blank 14rests against surface 179 so that the force exerted against the blankkey by the counterclockwise rotation of the cutters will not tend todeflect the key since it is being supported by support 177.

The operation of the key duplicating machine for cutting a two sided keyblank follows. First the key 18 to be duplicated and the key blank 14are secured in a key clamping structure, such as clamping structure 26discussed in detail below. The rotational movement of motor 32 istransferred to shaft 38 through transmission strip 50 and pulley 48whereby shaft 38, sliding bearings 92, 102 (shown in FIG. 3), andcutters 12A, 12B rotate together around axis 22. As the key to beduplicated moves between blades 124,160, the cutting guides 100, 110reciprocate towards and away from each other in accordance with theprofile of the grooves formed in opposite sides of the blade of key 18.The linear, reciprocal movement of cutting guides 100,110 causes thesliding bearings 92,102, milling cutters 12A, 12B to move towards andaway from each other. Springs 66 and 74 (shown in FIG. 3) disposedwithin rotational shaft 38 bias the cutters 12A,12B and cutting guides100,110 towards each other.

The cutting edges 180A, 182A and 180B, 182B of cutters 12A and 12B,respectively, are facing each other and constructed to cut into theopposite sides of the blade of key blank 14 to duplicate the grooves ofa two sided key 18 which is being duplicated. A unique aspect of theinvention is that the cutters 12A,12B reciprocate linearly along theaxis 22 while the key is being driven into and/or out of the spacebetween the rotating cutters in a direction perpendicular to axis 22.This movement can be distinguished from the prior art where the cuttingblade rotated at a set location about an axis.

Another unique aspect of the embodiment of the invention illustrated inFIGS. 1-3 is the ability to cut a single sided key blank. For this modeof operation, the pin-like handle 90, extending outward from end cap 76,is pulled outward against the bias of spring 74 and twisted to seat thepin 90 in groove 84. Next, pin shaped handle 148 of component 130 ismanually twisted from the position as illustrated in FIG. 3 and moved,under the bias of spring 146, into slot 142 so that rod 132 moves to theright. With this setup, spring 66 within shaft 38 exerts a biasing forcevia pin 70 against sliding sleeve 92 which in turn biases sliding sleeve102, cutting guide 110, and cutter 12C to the right into a position forcutting a single sided key blank which is clamped into a key clampingstructure such as key clamping unit 28 which is adapted for clamping asingle sided key 20 to be duplicated and a single sided key blank asillustrated in FIGS. 4A and 4E and discussed hereinafter. As with thecutting of a double sided key blank, the rotational movement of motor 32is transferred to shaft 38 through transmission strip 50 whereby shaft38, sliding bearings 92, 102, and cutters 12A, 12B, and 12C rotatetogether around axis 22. As the key to be duplicated moves against blade162, the cutting guide 110, sliding bearing 102 and milling cutter 12Cmove towards in a linear direction with respect to axis 22 through shaft38 in accordance with the profile of the grooves formed on the singleside of the blade of key 20. Spring 66 disposed within rotational shaft38 biases the cutter 12C and cutting guide 110 against the key blank andthe grooves formed on the blade of the key to be duplicated. Asdescribed with respect to the cutting of a two sided key, the cuttingedges 180C, 182C of cutter 12C are constructed to cut into the side ofthe blade of key blank 16 to duplicate the grooves of the single sidedkey 20 which is being duplicated. Here again, cutter 12C reciprocates inthe linear direction along the axis 22 while the keys are being driventowards and/or away from the rotating cutter 12C in a directionperpendicular to axis 22.

While any desired device for clamping keys can be incorporated withcutting unit 12, in accordance with a preferred embodiment of theinvention, a key clamping assembly 24 is mounted on machine chassis 30.As seen in FIGS. 1 and 2, clamping assembly 24 includes a support base200 having spaced bores 202 and 204 extending therethrough and locatedadjacent opposite sides thereof. Support rods 208 and 206 are slidablyreceived in bores 202 and 204, respectively, and are secured to thechassis at opposite ends by support components 210, 212, and 214, 216,respectively. A operating rod 218 is secured at one end to support base200 and has an end cap 220 at the opposite end. Rod 218 extends througha bore of spring support plate 222. A spring 224 is disposed betweenspring support plate 222 and end cap 220 to bias end cap 220 intoengagement with the peripheral surface of cam 34 so that the rotation ofthe cam by motor 36 causes the support base to reciprocate back andforth in a direction perpendicular to axis 22. A microswitch 221 ismounted on chassis 30 to engage cam 34 and turn off the machine 10 afterthe keys have been cut.

Referring now to FIG. 4A, there is illustrated a clamping unit 26 forclamping a two sided key blank 14 and a two sided key 18 to beduplicated in a single, joint clamping operation. Clamping unit 26includes an upstanding support 234 which is connected to support base200 by conventional means, such as bolts 232. Upstanding support 234 hasa lower section 236 and a narrow upper section 238 to form a shoulder240 at the intersection thereof. An intermediate key alignment plate 242having first and second side compression surfaces 244 and 246 and firstand second surface compression surfaces 245 and 247 mounted againstupper section 238, as shown in FIG. 4A. The mounted plate 242 is securedto the upper section 238 by spring biased pins 248 and 250. Anintermediate compression flange 252 has two bores through opposite sidesthereof in which are received mounting means. In the preferredembodiment one of the mounting means is a bolt 254 secured at one end tosupport 234 and at the other end to a compression unit 256. The othermounting means is an elongated bolt 258 secured at one end to thesupport base 200 and at the other end to compression unit 256 forconnecting all parts of the clamping unit 26 together. Clamping unit 26has two spaced slots 260 and 262 formed between the alignment plate 242and the shoulder 240 and the compression flange 252 for clamping the keyto be duplicated 18 and the blank key 14. The first compression surface244 of plate 242 is provided for compressing one surface of the key 18to be duplicated and the second compression surface 246 on its other endis provided for compressing one surface of the blank key 14 against theforward facing surface 264 of the upper section 238 of the clamping unit234 during the clamping operation, as described below. This compressioninsures that the two keys are correctly aligned with respect to eachother.

In addition, clamping unit 26 includes a compression unit 256, which canbe any conventional compression unit. In the preferred embodiment, thecompression unit 256 is connected to the clamping unit by bolts 254 and258 which extend through an upper flange 266. A compression spring 268is mounted on a central pin 270 having a shoulder 271 which compressesintermediate compression flange 252 the key 18 to be duplicated, theintermediate plate 242 and the key blank 14. Accordingly, thecompression power of compression spring 268 clamps both the key to beduplicated and the key blank in one operation and by one compressionpower.

A shut-off handle 272 for opening and closing the clamping unit 26 isconstructed to rotate around a shaft 274 connected to the compressionunit 256. One end of the shut-off handle 272 engages central pin 270 sothat by manually press on one end 276 of the shut-off handle theshoulder 278 at the other end of handle 272 pushes against a nut 281secured to central pin 270 and moves the central pin upward to relievethe compressive force from the clamping unit and allow the key 18 to beduplicated and the key blank 14 to be inserted or removed from the slots260 and 262, respectively. When the handle 272 is released, thecompressive power of spring 268 is again exerted against intermediateflange 252 to again apply compressive force to the clamping unit 26. Itwill be understood by an appropriate skilled person that the compressionunit which applies the compressive force can be any conventionalcompression unit.

Clamping unit 26 further includes a clamping guide 280 which has a firstposition, as shown in FIGS. 1 and 2, that insures that the key blank 14and the key 18 to be duplicated are correctly positioned with their tipends at the same location during by clamping operation. The clampingguide 280 is constructed to rotate away from the keys to a secondposition before the blank key cutting operation and to return to thefirst position after the cutting and duplicating key operation. Theclamping guide 280 comprises a guiding plate 282 which abuts against thetips of both the blades of the key blank and the key to be duplicatedwhen those keys are placed in the clamping unit 26. The guiding plate282 is connected to one side of a guiding plate arm 284, as shown inFIG. 1 which in turn is connected at its other end to one side of arotating rod 286 and to one end of a retrieving spring 288. Theretrieving spring 288 is connected at its opposite end to the clampingunit 26 so that the spring can rotate guiding plate 282 to the secondposition or to exert a force of rotation on the plate 282 when thelatter returns to its first positioning place depending on how thespring is adjusted. In this case said spring operates in one directionbias to cam surface 292. The rotating rod 286 is connected at its otherend to a member 290 with a cam surface 292. An adjustable sliding pin294 is connected to the chassis 30 by a rod 296 so as to adjust itslinear position whereby it engages cam surface 292 of member 290 torotate rod 286 when support base 200 moves in a linear direction awayfrom the cutting unit 12. Accordingly, the member 290 causes theclamping guide 280 to return to its first position after the key cuttingoperation against the bias of spring 288. It is also within the scope ofthe invention to operate the clamping guide in an opposite manner, i.e.to spring bias the guiding plate to the second position and rotate itback against the spring bias to the first position, in a differentconstruction, as will be appreciated by one skilled in the art.

The clamping unit 26 can also include a linear movable rod 300 arrangedto spread cutters 12A and 12B and their associated cutter blades 124 and160, respectively, during the forward movement support 200 so that thekey cutting operation only commences when the linear support 200 beginsto move back, that is away from the cutters 12A and 12B. The movablelinear rod 300 reciprocates within a hole 301 located through the upperintermediate plate 242 of clamping unit 26 and above the key 18 to beduplicated. Rod 300 has an enlarge cylindrical end 302 whose diameter isgenerally larger than the width of the blade of key 18, the other end ofrod 300 has a stopping nut 303. As the support 200 moves towards thecutter unit 12, the tip of cylindrical end 302 moves into the spacebetween cutter blades 124 and 160 and causes the cutters 12A and 12B tospread open to a distance greater than the width of the key to beduplicated. When the support reaches the end of its movement towards thecutters 12A and 12B, a rear section 304 of rod 300 having a diameterwhich is approximately equal to or less than the space between thecutters 12A and 12B before a key separates blades 124 and 160, as shownin FIG. 1, is disposed between the blades and they move back towardseach other. Then, as support 200 returns to its initial position, priorto the cutting operation, the section 302 is clamped by the cutters andthe rear section 304 of rod 300 which moves freely in hole 301 isbetween the cutter blades so that the cutter 12A and 12B engage the keyblank so that the cutting operation commences from the innermost portionof the blade as linear support 200 starts to move back. Thisconstruction is advantageous because it reduces the time of the cuttingoperation and insures a more precise duplication of the key to beduplicated.

While the compression unit 256, as illustrated in FIG. 4A, is effectiveto clamp the keys in a single operation as discussed above, analternative embodiment is illustrated in FIG. 4B wherein a compressionunit 310 can be used in conjunction with clamping unit 26 as illustratedin FIG. 4A. The compression unit 310 includes a screw shaft 312 movingwithin an upper flange 314 connected to an handle 316. By rotatinghandle 316 in one direction, the screw shaft 312 presses on theintermediate flange 252' in order to clamp the clamping unit 26.Rotation of handle in the opposite direction cause the relief ofclamping unit 26.

It can be appreciated that each of the cutters 12A and 12B of cuttingunit 12 are mounted on a different sliding bearing 92 and 102 forcutting grooves of a two sided key blank during the same linearmovement. Each of said cutters is guided by a different guiding bladewhich slides on a different side of the two sided key grooves, such thatthe duplication of grooves on both sides of the key blank is operated inone joint linear movement. Cutter 12C, as previously discussed isconstructed to enable the duplication of one sided key grooves. Thecutting blade 162 is jointly mounted on cutting guide 110 located onsliding bearing 102 on which cutter 12B is also mounted and will operateduring the one sided key duplication operation.

Referring again to FIGS. 1 and 4A and 4C, there is shown a clamping unit28 which is constructed to clamp especially but not limited a singlesided key blank 16 and a single sided key 20 to be duplicated. Clampingunit 28 includes an upstanding support 320 which is connected to supportbase 200 by conventional means, such as bolts 321. Upstanding support320 has a lower section 322 and a narrow upper section 324 to form ashoulder 326 at the intersection thereof. An intermediate key alignmentplate 328 has a first compression surface 330 at one end for compressingone surface of the key blank and a second compression surface 332 on itsother end for compressing one surface of the key to be duplicated duringclamping operation. The mounting plate 328 is secured to the uppersection 324 by spring biased pins 334 and 336. Clamping unit 28 has twospaced slots 338 and 340 formed between the alignment plate 328 and theshoulder 326 and an eccentric compression unit 342 for clamping the keyto be duplicated 20 and the blank key 16. The clamping unit includes acompression unit 342 which can be any conventional compression unit butin the preferred embodiment of the present invention the compressionunit, as illustrated in FIGS. 4A and 4C, has shoulders 344 connected tothe upper section 324 of support 320. The compression shoulders 344 eachhave a hole 346 disposed therethrough. An eccentric disk 348 disposedbetween the shoulders 344 is connected to a shut-off handle 350. Theeccentric disk has a hole 352 offset to the perimeter of the eccentricshaped disk. A pin 354 passes through the shoulder holes 346 and throughthe hole 352 disposed on disk 348 in order to allow the eccentric disk348 to rotate about the axis of pin 354. A compression component 356having two spaced shoulders 358 and 360, as shown in FIG. 4D, is mountedto slide on the upper section 324 of clamping unit to either movedownwards and press on the upper surface of the key to be duplicated inslot 340 or to be free so that the key can be either inserted or removedfrom the slot. One shoulder 362 of compression component 356 has twocompression surfaces 362 and 364 disposed on opposite ends thereof.Compression surface 362 is disposed with respect to disk 348 to receivepressure from the circumferential surface and the other compressionsurface 364 is located to exert a clamping force on the upper surface ofkey 20. The clamping operation is performed by manually rotating handle350 about pin 354 to rotate disk 348 so that the eccentric disk 348rotates and forces compression component 356 against key 20, which inturn is pressed against alignment plate 328. The alignment plate in turnpress against key 16 against shoulder 326. The result is that with theactuation of a single compression unit 342 both keys 16 and 20 areeither clamped together or released from the clamping unit 28.

Clamping unit 28 also includes a guiding unit 365, as illustrated inFIG. 1, for properly aligning the single sided key to be duplicated 20and the key blank 16 in the clamping unit. Guiding unit 365 has aguiding plate 366 connected to one end of a first arm 367. The oppositeend of the arm 367 is connected to a sleeve 368 having one end of asecond arm 369 secured thereto. The opposite end of arm 369 is connectedto a spring 371 which in turn is connected to support unit 200 byconventional means such as a screw 373. The sleeve 368 is constructed torotate about a pin 375 disposed therein and mounted to support unit 200.A second pin 377, connected to the chassis 30 by means such as a screw379, is disposed between pin 375 and arm 369. In operation of guidingunit 365, the guiding plate 366 is biased by spring 371 against theshoulders of the key blank and the key to be duplicated 20, as shown inFIGS. 1 and 4A. The guiding plate 366 acts to press the sides of theblades of both keys against the upper section 324 to properly align andsecure them in a parallel relation to each other. When the movablesupport 200 starts to move forward towards the cutting unit 12, pin 377engages arm 369 and causes arm 369 and arm 367 to rotate about pin 375which in turn causes plate 366 to disengage from key 20. Then, key 20can move to the cutter 12C without interference from guiding unit 365.When support 200 returns to its initial position, as shown, the pin 377relieves the engagement from arm 369 and allows spring 371 to rotate arm369 back to its initial position so that guiding plate 366 returns to aposition to again align the keys during the clamping operation.

Referring now to FIG. 4E, there is illustrated an alternative embodimentof a single sided key clamping unit 370 which can be substituted for thesingle sided key clamping unit 28 just described. Clamping unit 370incorporates a modified compression unit 372 which can replacecompression unit 342 with clamping unit 28 as illustrated in FIG. 4A.The compression unit 372 includes a shoulder 374 extending outward fromsupport 320' with a vertically disposed threaded hole 376 extendingtherethrough. Throughout the specification, primed numbers representstructural elements which are substantially identical to structuralelements represented by the same unprimed number. A threaded pin 378,having a conventional shut off handle 380 at one end, is rotatablymounted in hole 376. A compression element 382, as shown in FIG. 4E, issimilar to compression element 356 in FIG. 4D but has two spacedshoulders 384 and 386 at one end thereof and an elongated shoulder 390at the other side thereof as shown in FIG. 4F. Compression surfaces 392and 394 are located on opposite sides of shoulder 390. When assembled,the shoulder 374 extending from support 320' is disposed betweenshoulders 384 and 386 so that shoulders 390 and 384, and 386 are mountedto slide on the upper section 324' of the clamping unit to either movedownwards and clamp both keys 16 and 20 in place or to be freelysupported to allow the keys to be inserted or removed from slots 338'and 340'. The clamping operation is performed by manually turning handle380 and pin 378 towards against compression surface 392 which in turnpresses compression surface 394 of compression element 382 which in turnis pressed against alignment plate 328'. The alignment plate in turnpresses key 16 against shoulder 326'. As with the embodiment in FIG. 4A,with the actuation of a single compression unit 370, both keys 16 and 20are either clamped together or released from the clamping unit 28. Itcan further be appreciated that the innovation of the clamping units 28,constructed and operative in accordance with the present invention, isthat the key blank and the key to be duplicated are clamped in oneclamping unit with one clamping power. The vector of the power operateson both axis of the key blades.

Referring to FIG. 5, there is illustrated an alternative embodiment ofthe invention wherein a duplicating key machine 400 has a cutting unit402 with two cutters 12A and 12B which incorporates the operatingfeatures of the two cutters 12A and 12B of FIGS. 1-3. The duplicatingkey machine 400, in accordance with the present invention, includes amachine chassis 404 on which is mounted an electrical motor (not shown)for driving the cutting unit 402, key clamping support structure 24'which is movable in a linear direction transverse to axis 405, and a camdevice connected to a motor (not shown) for reciprocally moving clampingsupport structure 24' in the transverse direction to axis 405.

Reference is made now to the construction and parts of the cutting unit402 of the key duplicating machine 400 which is described in moregeneral terms since the operation is essentially identical to theoperation of the two sided key cutting portion of the key duplicatingmachine 10 described before. A hollow cylindrical shaft 406 is rotatablysupported at opposite ends within side bearings 40',42' mounted withintwo upstanding chassis supports 44', 46' respectively, which in turn aresecurely mounted to machine chassis 404. Shaft 406 is driven by a flywheel 48'. Milling cutter 12A is rigidly secured to a slidingcylindrical bearing 92' which is slidably mounted on the outerperipheral surface of shaft 406. Shaft 406 has two elongated boredsections 54' and 56' which open at opposite ends of the shaft.Diametrically opposed elongated slots 408A, 408B and 410A, 410B arelocated through the wall of shaft 406 adjacent the blind end of boredsections 54' and 56', respectively. A spring 66' is disposed in boredsection 54' and abuts against an end cap at the outer end of the boreand against an elongated, cylindrical pin 70' which extends throughslots 408A, 408B of shaft 406 for operational engagement with cutter12A, as discussed below. The head of a pin 72' is biased by spring 66'into engagement with pin 70'. A spring 74' is disposed in bored section56' and abuts against a hollow end cap mounted within the outer end ofthe bore 56'. The inner end of spring 74' engages against an elongated,cylindrical pin 86' which extends through slots 410A,410B of shaft 406for operational engagement with cutters 12B, as discussed below. Thehead of a pin 72' is biased by spring 74' into engagement with pin 86'.

A first sliding cylindrical bearing 92' is slidably secured about theouter peripheral surface of shaft 406 by pin 70' and adapted for slidinglinear movement with respect to the shaft along the direction of axis405. Milling cutter 12A is mounted against an inner shoulder of bearing92' so that the ends of pin 70' are received in slots 93' extendingradially inward from central opening of cutter 12A to rotate cutter 12Awith the rotation of shaft 406. Abutted against cutter 12A is a circularbearing plate 94'. A locking nut 96' is secured to the outer end ofsliding cylindrical bearing 92'. A cylindrical end section of nut 96' isprovided to mount a cutting guide 100'. The locking nut 96' secures theguide 100' against bearing plate 94' which in turn secures millingcutter 12A to sliding bearing 92'. For reasons previously explained,cutting blade 12A both rotates about and reciprocates axially to axis405 with cylindrical bearing 92' while cutting guide 100' is secured sothat it only reciprocates with milling cutters 12A and cylindricalbearing 92' axially to axis 405.

A second sliding cylindrical bearing 412, which is essentially identicalto bearing 92', is slidably secured about the outer peripheral surfaceof shaft 406 by pin 86' and adapted for sliding, reciprocal, linearmovement with respect to the shaft along the direction of axis 405. Thefirst and second sliding cylindrical bearings 92' and 412 are normallyabutted against each other. Milling cutter 12B is mounted against aninner shoulder of bearing 412 so that the ends of pin 86' are receivedin slots extending radially inward from the central opening of cutter12B to rotate cutter 12B with the rotation of shaft 406. Abutted againstcutter 12B is bearing plate 112'. A locking nut 96' is secured to theouter end of sliding cylindrical bearing 412. A cylindrical end sectionof nut 96' is provided to mount a cutting guide 100'. The locking nut96' secures the guide 100' against bearing plate 112' which in turnsecures milling cutter 12B to sliding bearing 412. As with millingcutter 12A, milling cutter 12B both rotates about and reciprocateslinearly to axis 405 with cylindrical sliding bearing 412 while cuttingguide 100' is secured so that it only reciprocates axially with millingcutter 12B and cylindrical bearing 412 axially to axis 405.

According to the invention cutting guides 100' with guiding blades 124secured thereon, as shown in FIG. 5A, have U-shaped end sections 128'which are mounted to identical pin components 414 which allow thecutting guides 100' to reciprocate in the linear direction along axis405 while preventing rotational movement thereabout. The pin components414 are secured to the upstanding chassis supports 44' and includeelongated pin 416 having an enlarged head 418 at the free end. The pins416 extends beneath U-shaped ends 128' whereby the latter slidablyengage pins 416 and reciprocate in a linear direction between outerheads 418 and an inner stops 420 while preventing rotational movementthereabout.

The operation of the key duplicating machine 400 for cutting a two sidedkey blank is substantially identical to the operation of the machine 10described before. It is further within the scope of the invention forduplicating machine 400 to cut both single sided and double sided keyblanks. The keys are secured in a key clamping structure, such asclamping units 26 or 28, as previously discussed, mounted on areciprocal support 200'. It is also in within the terms of the presentinvention to use any other appropriate key clamping mechanism or supportmechanism to direct the keys into the pair of milling cutters 12A and12B.

Referring to FIG. 6, there is illustrated an alternative embodiment ofthe present invention wherein a duplicating key machine 450 has acutting unit 452 with a single milling cutter 12A which incorporates theoperating features of the single cutter 12C of FIGS. 1-3. Theduplicating key machine 450, in accordance with the present invention,includes a machine chassis 453 on which is mounted an electrical motor(not shown) for driving the cutting unit 452, a key clamping supportstructure 24" which is movable in a linear direction transverse to axis454, and a cam device (not shown) connected to a motor (not shown) forreciprocally moving the clamping support structure 24" in the transversedirection to axis 454 in the manner discussed before with regards to theembodiment shown in FIGS. 1-3. Support structure 24" can also be movedmanually without a cam device.

Reference is made now to the construction and parts of the cutting unit452 of the key duplicating machine 450 which is described in moregeneral terms since the operation is essentially identical to theoperation of the single sided key cutting portion of the key duplicatingmachine 10 described before. A hollow cylindrical shaft 456 is rotatablysupported within a side bearing 40" mounted on an upstanding chassissupport 44" which in turn is secured to machine chassis 453. Shaft 456is driven by a fly wheel 48". Milling cutter 12A is rigidly secured to asliding cylindrical bearing 461 which is slidably mounted on the outerperipheral surface of shaft 456. Shaft 456 has an elongated boredsection 54" which opens at one end of the shaft. Diametrically opposed,elongated slots 458, 460 are located through the wall of shaft 456adjacent the blind end of bored section 54". A spring 66" is disposed inbored section 54" and abuts against an end cap at the outer end of thebore against the head of a pin 72", which in turn abuts a cylindricalpin 70" that extends through slots 458,460 of shaft 456 for operationalengagement with cutter 12A, in the manner previously discussed.

Sliding cylindrical bearing 461 is slidably secured about the outerperipheral surface of shaft 456 by pin 70" and is adapted for sliding,linear, reciprocating movement with respect to the shaft 456 along thedirection of axis 454. Milling cutter 12A is mounted against a lockingend nut 462 secured to an outer end of bearing 461 so that the ends ofpin 70" are received in a slot 93" extending radially inward fromcentral opening of cutter 12A to rotate cutter 12A with the rotation ofshaft 456. Abutted against cutter 12A is a circular bearing plate 94". Acylindrical end section of bearing 461 is provided to mount a cuttingguide 100". The locking end nut 462 forces the cutter 12A against thebearing plate 94" which in turn presses the guide 100" against thecylindrical end section of sliding bearing 461 in order to allow theguide 100" to slide on bearing 461. For reasons previously explained,cutting blade 12A both rotates about and reciprocates axially to axis454 with cylindrical bearing 461 while cutting guide 100" is mounted onbearing 461 so that it only reciprocates with cutting blade 12A andcylindrical bearing 461 axially to axis 454.

According to the invention, cutting guide 100", as shown in FIG. 6, hasa U-shaped end section 128" which is mounted to a pin component 414"that allows the guide 100" to reciprocate in the linear direction withrespect to axis 454 while preventing rotational movement thereabout.

The operation of the key duplicating machine 450, for cutting a singlesided key blank, is substantially identical to the operation of themachine 10 described before. Duplicating machine 450 is especiallydirected to but not limited to cutting single sided key blanks. The keysare secured in a key clamping unit, such as the clamping unit 26previously discussed, and mounted on a reciprocating support 200". It isalso in within the terms of the present invention to use any otherappropriate key clamping device to direct the keys into the millingcutter 12A.

Referring to FIG. 7, there is illustrated an alternative embodiment ofthe present invention wherein a duplicating key machine 470 is similarto the key duplicating machine of FIG. 1. Referring now to FIG. 7, acutting unit 472 includes milling cutters 12A,12B and 12C, mounted onfirst and second hollow rotational shafts 476 and 478 having anelongated internal rod 480 extending therethrough. The first rotationalshaft 476 is slidably disposed within a bearing 482 secured to a firstchassis support 44'". Rotational shaft 476 has one end coupled to atransmission wheel 48'" that is driven by a belt connected to thetransmission wheel of a motor (not shown), as previously discussed. Afirst end of shaft 476 is connected by conventional means such as a pin483, to the longitudinal internal rod 480 disposed within the internalbore of rotational shaft 476. The second opposite end of firstrotational shaft 476 is coupled to cutter 12A and fixedly mountedthereto by pins 484 and a threaded end nut 486 secured to shaft 476. Afirst guiding unit 100'" is secured to rotational shaft 476 to enableguiding unit 100'" to move linearly with the rotational shaft 476 andcutter 12A along the axis 488 without rotating during the rotationalmovement of the shaft and the cutter. The cutting unit 472 also includesa second rotational shaft 478 disposed within a second bearing 490secured within a second chassis support 46'". The first outer end ofshaft 478 has diametrically opposed slots 479 and 481. Bearing 493,located adjacent to the first end of the second rotational shaft 478,has diametrically opposed slots 492, 494 which receive a pin 496 that iscoupled to the elongated internal rod 480 and extends through slots 479,481, as shown in FIG. 7A. The end of bearing 493 has a groove 495. Pin496 transfers the rotational movement from the internal rod 480 to thesecond rotational shaft 478 and bearing 493. The pin 496 slides withinthe two slots 479, 481 of shaft 478 and within slots 492,494 provided onbearing 493. The second opposite end of second rotational shaft 478 iscoupled to cutters 12B and 12C by pins 498 and 500, respectively, and athreaded end nut 501 secured to shaft 478. The second end of shaft 478communicates with a second guiding unit 502 which is constructed in amanner similar to guiding unit 110 of machine 10 to move with cutters12B and 12C and with the second rotational shaft 478 linearly along theaxis 488 through the second rotational shaft without rotating during therotational movement of cutters 12B and 12C and the second rotationalshaft, as discussed below. The second guiding unit 502 includes firstand second guiding blades 160'" and 162'". Blade 160'" is locatedadjacent to cutter 12B for guiding cutter 12B during the cuttingoperation. Guiding blade 162'" is located adjacent to cutter 12C forguiding cutter 12C during cutting operation. The first and secondguiding units 100'" and 502 each have U-shaped end sections 128'" whichare mounted to components 130'" and 170'", respectively, which allowguide units 100'" and 502 to move in a linear direction along axis 488while preventing rotational movement thereabout.

Referring again to FIG. 7, the outer end of second shaft 478 has twodiametrically opposed, longitudinal slots 479 and 481. A sliding disk508 having a central bore therethough is disposed adjacent to the outerend of sliding shaft 478 and within the open bore of bearing 493disposed adjacent to the outer end of bearing 490 with the rod 480extending through the bore. As shown in FIG. 7B, two pins 510 aresecured to disk 508 within bearing 493 and project outward through slots492 and 494 for sliding engagement therewith. One side of the slidingdisk 508 presses the end of second rotational shaft 478 and the otherend of the sliding disk is engaged by one end of a compression spring511 located about the longitudinal rod 480. The opposite end of thecompression spring 511 is abutted against a disk 512 fixedly coupled tothe longitudinal rod by conventional means such as pin or screw 514. Oneend of the compression spring 511 is biased against sliding disk 508which in turn biases the second rotational shaft 478 with cutter 12Btoward cutter 12A. The opposite end of compression spring 511 is abuttedagainst the disk 512 in order to pull the longitudinal rod 480 connectedto rotational shaft 476 by pin 483 and push first rotational shaft 476with cutter 12A towards cutter 12B. The biasing force of compressionspring 511 on the sliding disk 508 and on the disk 512 biases cutter 12Awith guiding unit 100'" and blade 124'" towards cutter 12B with guidingunit 502 and blade 160'" toward each other.

To duplicate two sided keys, it is preferred to use cutters 12A and 12Bin a manner as previously described with respect to FIGS. 1-3. Toduplicate a one sided key, it is preferred to use cutter 12C in themanner described in FIGS. 1-3. However, the single cutter 12C can beused to cut two sided keys by simply turning both the key to beduplicated and the blank key over after the grooves in the first side ofthe blank are cut. Of course, cutters 12A and 12B can be used toduplicate a one sided key, if desired.

In order to use cutter 12C for cutting a single sided key, sliding disk508 must be moved to the end of bearing 493 and twisted in such way thatpins 510 will engage groove 495, as illustrated in FIG. 7C. Also,component 130'" is adjusted by turning twisting handle 148'" so that thehandle is based to the right within slots 142'" to permit the end cap134'" to move from a corresponding distance to the right. When pin 510is within groove 495, sliding disk 508 does not press the end of secondrotational shaft 478 but only acts as a stop for spring 511 to pressagainst disk 512 to pull the first rotational shaft 476 by means ofinternal rod 480 and pin 483 and first rotational shaft 476 towardssecond rotational shaft 478 and exert a biasing force against the secondrotational shaft, so that compression spring 511, in effect, biasescutter 12C, guiding arm 502 and guiding blade 162'" to perform thecutting and duplicating operation.

Referring now to FIG. 8, there is illustrated another preferredembodiment of a key duplicating machine 520 similar to the preferredembodiment as described in FIG. 7. The cutting unit 522 includes arotational shaft 524 having a cutter 12A and a guiding unit 100""secured thereto. Shaft 524 is mounted within a bearing 525, which inturn is secured to a support 530 connected to the chassis. An externalcompression spring 526 surrounds rotational shaft 524 between guidingunit 100"" and a shoulder 528 disposed on chassis support 530. Theconstruction of machine 520, as illustrated in FIG. 8, highlights themain features of the present invention. That is, a single shaft 524serves as a support for the linear movement of cutter 12A and itsassociated guiding unit 100"". As discussed in detail before, anydesired type of clamping unit can feed the key to be duplicated and thekey blank towards the cutter 12A. The embodiment shown in FIG. 8 can beused for cutting both single sided and double sided keys. This design isadvantageous because the reduced number of features results in low costproduction and maintenance, simplicity of operation, and efficiency ofthe machine.

Referring to FIG. 9, there is illustrated an embodiment of a keyduplicating machine 550, similar to FIG. 8, wherein a linearly movableshaft 524' is mounted in a bearing 525'. The shaft 524' is biased by aspring biased pin 552, mounted on a support 554 which in turn can beconnected to upstanding support 530'. The guiding unit and key clampingunit (not shown) can be provided by conventional mechanisms as desired.

Referring to FIG. 10, there is illustrated an embodiment of the keyduplicating machine 550 wherein a conventional, circular, plate-likecutting blade 560 is substituted for the cup shaped cutting blade of thepresent invention.

While the cutting blade of the present invention is typically a cupshaped blade, it is within the terms of the invention to substitute anytype of cutting blade, such as a circular, plate-like blade.

It is apparent that there has been provided in accordance with thisinvention a key duplicating machine and the method of operating themachine that satisfy the objects, means and advantages set forthhereinbefore. While the invention has been described in combination withembodiments thereof, it is evident that many alternatives,modifications, and variations will be apparent to those skilled in theart in light of the foregoing teachings. Accordingly, the invention isintended to embrace all such alternatives, modifications and variationsas fall within the spirit and scope of the appended claims.

We claim:
 1. A key duplicating machine comprising:a chassis; a cutterunit having at least one cutter secured to said chassis, said cutterunit comprising: a shaft having a longitudinal axis extendingtherethrough mounted to said cutter unit so as both rotate about andreciprocate linearly with respect to said longitudinal axis, said shafthaving first and second opposite ends, a first end of said shaftconnected to a drive system for transferring rotational movement to saidshaft for rotating said shaft around said longitudinal axis, and asecond end of said shaft secured to said at least one cutter, said shaftand said at least one cutter secured thereon rotate together around saidaxis and move linearly along said axis; a spring biased element mountedon said key duplicating machine to bias said shaft in a linear directionalong said longitudinal axis.
 2. A key duplicating machine comprising:achassis; at least one cutter unit secured to said chassis, said cutterunit comprising:at least one shaft having a longitudinal axis extendingtherethrough wherein said shaft is adapted for connection to a drivesystem for transferring rotational movement to said at least one shaftaround said longitudinal axis; and at least one cutter secured to saidshaft whereby said cutter rotates around said longitudinal axis andreciprocates in a linear direction along said longitudinal axis; atleast one spring biasing said at least one cutter; and at least oneguiding unit for reciprocally moving said at least one cutter in alinear direction along said longitudinal axis in accordance with thegrooves on a blade of a key to be duplicated.
 3. The key duplicatingmachine according to claim 2 wherein said at least one cutter is acup-shaped milling cutter.
 4. A key duplicating machine comprising:achassis; at least one cutter unit mounted on a support secured to saidchassis, said cutter unit comprising:at least one shaft having alongitudinal axis extending therethrough and being adapted forconnection at one end to a drive system for transferring rotationalmovement to said shaft about said longitudinal axis; and at least onecutter mounted to said shaft whereby said cutter rotates around andreciprocates in a linear direction along said longitudinal axis; and atleast one guiding unit for reciprocally moving said at least one cutterin a linear direction along said longitudinal axis in accordance withthe grooves of a key to be duplicated.
 5. The key duplicating machineaccording to claim 4 further including a key clamping structure forsecuring a key to be duplicated and a blank key, said key clampingstructure being mounted on said chassis for reciprocal movement in aperpendicular direction with respect to said longitudinal axis.
 6. Thekey duplicating machine according to claim 4 wherein said at least onecutter is a cup-shaped milling cutter.
 7. The key duplicating machineaccording to claim 4 wherein at least one spring biases both said atleast one cutter and said at least one guiding unit such that said atleast one cutter is moved linearly in one direction by the bias of saidspring and in the opposite direction by said guiding unit.
 8. The keyduplicating machine according to claim 4 wherein said at least onecutter and said at least one guiding unit are both in communication withat least one biasing spring such that said cutter is moved linearlyalong said longitudinal axis in one direction by the biasing force ofsaid spring and in the opposite direction along said longitudinal axisby said guiding unit.
 9. The key duplicating machine according to claim4 wherein said drive system includes an electric motor operativelyconnected to said first end of said shaft.
 10. The key duplicatingmachine according to claim 4 wherein said cutter is secured to a bearingslidably mounted on said shaft so that said bearing with said cutter andsaid shaft rotate together around said longitudinal axis of said shaftand said bearing with said cutter can reciprocate linearly along saidaxis.
 11. A key duplicating machine comprising:a chassis; at least onecutter unit mounted on a support secured to said chassis, said cutterunit comprising: at least one shaft from at least one part having alongitudinal axis extending therethrough and being adapted forconnection at one end to a drive system for transferring rotationalmovement to said shaft around said longitudinal axis; and at least twocutters securely mounted on said at least one shaft to both rotatearound said longitudinal axis and to reciprocate linearly along saidlongitudinal axis; at least one key clamping unit for securing a key tobe duplicated and a blank key, said key clamping unit being mounted onsaid chassis for reciprocal movement in a perpendicular direction withrespect to said longitudinal axis; at least two guiding units each beingin communication with one of said at least two cutters, each of saidguiding units being adapted for sliding engagement with grooves on theblade of said key to be duplicated for causing reciprocating movement ofsaid cutter communicating thereto in a linear direction along saidlongitudinal axis; and at least one spring biasing at least one of saidguiding units and a corresponding one of said cutters communicatingthereto such that each of said cutters is moved linearly in onedirection along said longitudinal axis by the bias, of said at least onespring and in the opposite direction by its corresponding guiding unit.12. The key duplicating machine according to claim 11 further includingtwo bearings mounted on said shaft wherein each of said bearings has oneof said cutters secured thereto and engages one of said guiding unitssuch that each of said bearings can rotate with said shaft to rotatesaid cutter around said longitudinal axis, and each of said bearingsreciprocates linearly on said shaft along said longitudinal axis causingits corresponding cutter to reciprocate linearly along said axis. 13.The key duplicating machine according to claim 12 further includingmeans for operating each of said bearings by said at least one spring.14. The key duplicating machine according to claim 13 wherein said atleast two cutters are each secured to at least one of said bearings sothat said bearing, said shaft and said two of said cutters rotate aroundsaid longitudinal axis.
 15. The key duplicating machine according toclaim 14 wherein said at least two cutters secured to said at least oneof said bearings reciprocate together with said at least one of saidbearings in the same linear direction along said longitudinal axis. 16.The key duplicating machine according to claim 9 wherein said at leastone bearing having at least one cutter secured thereon is connected withsaid at least one guiding unit and communicates with said at least onespring.
 17. The key duplicating machine according to claim 11 whereinsaid drive system includes an electric motor operatively connected tosaid first end of said shaft.
 18. At least one clamping unit forclamping a blank key and a key to be duplicated mounted on a keyduplicating machine having at least one cutter unit, said at least oneclamping unit comprising:a clamping support having at least two spacedslots for receiving a key to be duplicated and a blank key; acompression unit connected to said clamping support for providing acompressive force to clamp said key to be duplicated and said blank keywithin said clamping support whereby said key to be duplicated and saidblank key are clamped in said two spaced slots of said clamping supportby said compressive force such that said key to be duplicated and saidblank key are both clamped with said compressive force which pressessubstantially up to the center of both said key to be duplicated andsaid blank key; said compression unit including a compression handlewhich engages a compression element and provides said compressive forceto jointly clamp said key to be duplicated and said blank key withinsaid clamping support by the same operation of said compression handleand to jointly release said key to be duplicated and said blank key fromsaid clamping unit by a release operation of said compression handle.19. The clamping unit according to claim 18 further including:said atleast one cutter unit comprising at least one cutter secured on a shaft;and means for providing relative movement between said at least onecutter unit and said clamping unit for duplicating and cutting the keyblade of said blank key.
 20. The clamping unit according to claim 18further including a key alignment plate disposed between two spacedslots for transferring said compressive force between said key to beduplicated and said blank key such that said compressive force clampingsaid key blank in one of said slots is transferred to clamp said key tobe duplicated in the other of said slots.
 21. The clamping unitaccording to claim 20 wherein said key alignment plate has first andsecond compression surfaces at opposite ends thereof, said firstcompression surface adapted to engage one side of said key to beduplicated and said second compression surface adapted to engage oneside of said blank key whereby both of said keys are compressed againsta surface located on said clamping support to ensure that said key to beduplicated and said blank key are correctly aligned with each other. 22.The key duplicating machine according to claim 11 wherein said at leasttwo cutters are cup-shaped milling cutters.
 23. The clamping unitaccording to claim 22 further including a spring biased for providingsaid compressive force to clamp said blank key and said key to beduplicated.
 24. The clamping unit according to claim 22 wherein saidcompressive force is provided by an eccentric disk secured to saidcompression handle for providing said compressive force to clamp saidblank key and said key to be duplicated.
 25. The clamping unit accordingto claim 22 wherein said compression unit includes a threaded shafthaving a handle at one end being threadedly connected to the clampingunit, said threaded shaft having a second opposite end to engage withsaid compression element for transferring said compressive force toclamp said key blank and said key to be duplicated.
 26. The clampingunit according to claim 18 wherein said compressive force issubstantially directed through the center axis of both of said keyswhereby the maximum compressive force is applied to both said key to beduplicated and said blank key.
 27. The clamping unit according to claim18 further including:a chassis on which said clamping unit is mounted;said at least one cutter unit comprising at least one cutter for cuttingsaid blank key to the profile of said key to be duplicated, said atleast one cutter unit mounted to a chassis of said key duplicatingmachine; and means for providing relative movement between said clampingunit and said at least one cutter unit.
 28. The clamping unit accordingto claim 27 further including a guiding unit having a guiding meanspivotally mounted to said clamping unit to engage said blank key andsaid key to be duplicated and to press them against said clampingsupport to insure that said keys are properly aligned with respect toeach other prior to being clamped by said compressive force.
 29. Theclamping unit according to claim 27 further including a clamping guidemounted to said clamping unit, said clamping guide including a guidingmeans connected to a spring biased rotating pin, said guiding meanshaving a first position for positioning said guiding means to the tipends of said blank key and said key to be duplicated when said keys areinserted in said slots of said clamping support prior to applying saidcompressive force and moving said guiding means away from said tip endsof said keys as said clamping unit is moved.
 30. The key duplicatingmachine according to claim 2 further including a movable supportincluding two clamping units mounted on said key duplicating machine,said clamping units each adapted for clamping a blank key and a key tobe duplicated.
 31. The key duplicating machine of claim 30 furtherincluding at least one key clamping unit for securing said key to beduplicated and a blank key, said key clamping unit being mounted on saidchassis for reciprocal movement in a perpendicular direction withrespect to said longitudinal axis.
 32. The key duplicating machine ofclaim 31 further including at least two cutter units secured to saidchassis, each of said two cutter units comprising:at least one shafthaving a longitudinal axis extending therethrough said shaft beingadapted for connection to a drive system for transferring rotationalmovement to said shaft around said longitudinal axis; and at least onecutter secured to said shaft whereby said cutter rotates around saidlongitudinal axis and reciprocates in a linear direction along saidlongitudinal axis; at least one spring biasing said at least one cutter;and at least two guiding units each for reciprocally moving one of saidat least two cutters in a linear direction along said longitudinal axisin accordance with the grooves of said key to be duplicated.
 33. The keyduplicating machine of claim 32 wherein said at least one shaft of eachof said two cutter units comprise first and second shafts, respectivelythat communicate to transfer rotational movement between said first andsecond shafts, and on each of said first and second shafts is securedfirst and second of said at least one cutter, respectively.
 34. The keyduplicating machine of claim 33 wherein said first and second shafts arefirst and second hollow rotational shafts having a longitudinal axisextending therethrough, said first and second hollow shafts having anelongated internal rod extending therethrough and having said first andsecond cutters mounted thereon, respectively;said first rotational shaftbeing slidably disposed within a first cutter unit secured to saidchassis, said first rotational shaft having a first end coupled to adrive system for transferring rotational movement to said first shaftaround said longitudinal axis, said first shaft being connected to saidinternal rod and a second opposite end of said first rotational shaftbeing securely coupled to said first of said cutters; said secondrotational shaft being slidably disposed within a second cutter unitsecured to said chassis, a first end of said second rotational shaftbeing securely coupled to said at least one of said second of saidcutters and a second end of said second shaft communicating with saidinternal rod whereby rotational movement is transferred from said firstshaft to said second shaft; first and second guiding units eachcommunicating with one of said first and second cutters, said first ofsaid guiding units being in sliding engagement with grooves on the bladeof said key to be duplicated for causing reciprocating movement of saidone or more of said first and second of said cutters connected theretoin a linear direction along said longitudinal axis.
 35. The keyduplicating machine of claim 34 wherein said at least one spring is acompression spring located about said internal rod for biasing at leastone of said rotational shafts and one of said guiding units in onedirection along said longitudinal axis and said other rotational shaftand the other of said guiding units in the opposite direction along saidlongitudinal axis.
 36. The key duplicating machine of claim 35 whereinsaid drive system includes an electric motor operatively connected tosaid first end of said first shaft for transferring rotational movementto said first shaft and to said second shaft.
 37. The key duplicatingmachine of claim 35 including means for compressing said spring withrespect to said internal rod whereby said first and second shafts movetogether in the same direction so that only a cutter on said secondshaft and said guiding unit are able to perform the cutting of saidblank key.
 38. The key duplicating machine of claim 37 wherein saidsecond shaft has said first and second cutters secured thereto whichrotate together around said axis and move linearly with said shaft alongsaid axis.
 39. The key duplicating machine of claim 38 wherein said saidfirst and second cutters secured to said second shaft move rotationallywith said second shaft around said axis and linearly along said axiswith said guiding unit.